Google Sites led the U.S. core search market in February with 65.5 percent of the searches conducted, followed by Yahoo! Sites (16.8 percent), and Microsoft Sites (11.5 percent), according to February 2010 U.S. search engine rankings released by comScore.

Ask Network captured 3.7 percent of the search market, followed by AOL LLC with 2.5 percent.

Americans conducted 14.5 billion searches in February, down 5 percent from January. Google Sites accounted for 9.5 billion searches, followed by Yahoo! Sites (2.4 billion), Microsoft Sites (1.7 billion), Ask Network (540 million) and AOL LLC (358 million).

In the February analysis of the top properties where search activity is observed, Google Sites led the search market with 13.5 billion search queries, followed by Yahoo! Sites with 2.5 billion queries and Microsoft Sites with 1.7 billion. Facebook.com experienced significant growth during the month with a 10-percent increase to 436 million searches, while craigslist, inc. jumped one position to #5 with 629 million searches.